This invention relates generally to a new and improved method and apparatus for forming a continuous railroad track and is more particularly concerned with a new and improved method and apparatus comprising a number of individual components coacting to produce a continuous railroad track much more quickly, more economically and more efficiently than has heretofore been possible. While the disclosure hereinafter set forth is primarily directed to forming a continuous railroad track, it will be evident that the method and apparatus is likewise applicable for forming, for example, a continuous pipeline and other like continuous length articles.
For a number of years it has been evident that the use of railroad tracks in the form of rail sections welded together to form a continuous strip is particularly desirable because such a construction not only increases the riding comfort of railroad passengers and reduces the shock and vibration to which rail freight is subjected but, at the same time, is substantially trouble-free and, hence, requires considerably less maintenance of rolling stock and track, than tracks of the type employing individual rail sections bolted or otherwise secured together. At the present time, the method and apparatus for forming a continuous rail is generally well established, and is disclosed in U.S. Pat. Nos. 3,982,091; 4,103,139 and 4,270,036, as well as other U.S. and foreign patents. However, in the context of these patents, the continuous rail which is formed is on the order of up to one quarter mile in length. These continuous rails are loaded onto flat cars or the like lined up adjacent the welding apparatus, and ultimately transported to an area where they are laid to form a railroad track. The flat cars may have loaded thereon a sufficient number of these continuous rails to form a continuous track many miles in length.
The present invention is primarily concerned with the method and apparatus for welding together these continuous rails to form the continuous track. In addition, a new and improved welding apparatus which can be used to form both continuous rails and a continuous track is disclosed.
In the past, various methods have been utilized to form a continuous track, however, these methods generally are far from satisfactory, for one reason or another. For example, the continuous rails have been mechanically connected together, in much the same fashion as ordinary rail sections presently are mechanically connected together, and then subsequently welded by hand. This method is not generally acceptable in view of the difficulty in physically handling the long lengths of continuous rails and the difficulty in providing a good weld between the joined lengths of rail. Other methods utilize apparatus to flash weld the rails together, however, the equipment required to provide the weld is extremely complex and essentially utilizes brute strength to manipulate the rails. These methods also encounter considerable difficulty as a result of the material consumed during the welding operation, hence these methods likewise are not entirely acceptable.
Accordingly, it is an object of the present invention to provide a new and improved method and apparatus for forming a continuous rail.
More particularly still, it is an object to provide a new and improved method and apparatus for forming a continuous track, be welding together previously formed continuous rails.
A still further object is to provide a new and improved welding apparatus.
The foregoing and other objects are realized, in accordance with the present invention, by providing a mobile welding plant in combination with, for example, a string of flat cars for transporting a number of already formed continuous rails, another flat car or the like carrying means such as a winch and other related apparatus for delivering the individual continuous rails to the mobile welding plant, and another flat car or the like transporting a puller or pusher apparatus for controlling the movement of the continuous track which is formed, in and from the mobile welding plant. In order to explain the method of forming the continuous track, assume that one or more continuous rails already have been welded together to form the start of the continuous track. This length of continuous track is moved out of the mobile welding plant by the operation of the puller apparatus and laid on the ties of the railroad bed, with the end of this continuous track located in the welding apparatus at its center. One of the continuous rails is delivered by means of the winch into the mobile welding plant, with its end opposite the end of the continuous track at the center of the welding apparatus. The ends of the continuous rail and the continuous track then are clamped and vertically and horizontally aligned, all as more specifically described below, in preparation to forming the weld between the ends thereof. As is generally well known, a flash butt welding operation is carried out under advance, return and upsetting movements carried out with the secondary voltage applied. Normally, in forming the continuous rail, this is not a particularly difficult operation to perform since the short rail section being welded to the longer segment of the continuous rail already formed is the one which is manipulated or moved. However, in welding the continuous rail which may be a quarter mile in length to the continuous track which may be many miles in length, it is apparent that it is exceedingly difficult to move either of these two lengths of rail. Under such circumstances, it would appear obvious that it still is more practical to move the continuous rail rather than the continuous track, since it is much shorter in length even though it may be a quarter of a mile in length. As indicated above, in other methods, this has been done, but it requires the application of brute strength to do so. As a result, the apparatus performing this operation is complex and necessarily heavy in both structure and capability. Contrary to what has previously been attempted, and that which appears to be the obvious expedient, in accordance with the method of the present invention, the end of the longer continuous track is moved relative to the end of the shorter continuous rail to provide the necessary advance, retract and upsetting movements. The continuous track extends a considerable distance from its end at the center of the welding apparatus, and there is a relatively long loop of approximately 50-100 feet in length spanning the distance from the puller apparatus to where the continuous track engages the ties of the railroad bed upon which it is being laid. Normally, such a rail is considered to be rigid, but long lengths of rail such as the long loop of approximately 50-100 feet in length actually is quite flexible, at least sufficiently flexible to permit the end of the continuous track to be moved in the welding apparatus to provide the necessary advance, retract and upsetting movements to form the weld. Accordingly, advantage is taken of this discovered phenomenon, to easily form the weld.